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Tuesday, 7 February 2012

Working memory is like a neural memo-pad. People with higher working memory capacity can hold more items in mind whilst solving a concurrent problem or performing a distracting task. There's been some excitement lately about the possibility that working memory can be improved through training, with knock-on benefits for IQ and academic attainment. A new study suggests such training should come with a footnote: "Improving your working memory could affect your perception of time".

James Woehrle and Joseph Magliano divided 99 students into two groups according to whether they had high or low working memory capacity. Next, the students solved subtraction problems in their heads. They were told the maths was their primary task but an extra challenge was to solve the problems for a certain duration, as judged by their own internal sense of time: either two minutes or four minutes.

The intriguing finding is that time went faster for the students with higher working memory capacity. When tasked with doing the maths for four minutes, they tended to work for longer, estimating that the time was up later than the low working memory participants.

What was going on? Why should having more working memory speed up the passage of time? Woehrle and Magliano said the finding was consistent with a popular account of time estimation, which posits that pulses are released by an internal pacemaker and accumulate in a counter. More pulses in the counter suggests more time has passed. Crucially, this process is gated by attention. When we pay attention to time, each pulse makes it into the counter and the passage of time feels slower. By contrast, if our attention is focused elsewhere, fewer pulses make it into the counter, as if less time has passed than really has (i.e. giving the subjective feeling of time having flown).

According to Woehrle and Magliano's Working Memory Capacity Hypothesis - the students in the current study with more working memory were able to allocate their attention almost entirely on the primary maths task. This benefited their maths performance but meant they were less vigilant of pulses accumulating in their internal clock. By contrast, the low working memory students couldn't help but allocate some attention to the secondary time-keeping task, making them more aware of the passage of time. As a consequence the low working memory students' time perception was actually more accurate but their maths performance suffered. The researchers said this evidence could have "profound implications in academic situations ... low working memory students may 'think' too much about how much time they put into their school work."

The new findings complement previous research showing that greater working memory capacity is associated with more accurate time perception, when time perception is the primary task. In this case, having more working memory allows for greater vigilance of the internal pacemaker and counter. Indeed, in the current study, the time perception of the higher working memory group was superior in a control condition in which they only had to estimate the passage of time.

11 comments:

Is it possible that the high working memory group is more motivated, smarter or enjoyed the task more? "time flies when you are having fun." I imagine the low working memory group would be bored during the task. Did they control for IQ? They say the high WM group did better on the task. I wonder what the results would be if they only compared similar performances.

Working memory capacity is correlated with IQ, so that may contribute to the variance accounted for in this study by their WM measure. Quasi-experimental designs like this can't rule out shared variance from other sources of individual differences. But, the important thing here was the trade off in performance on the math and time tasks.

Could this mean that people with a higher working memory capacity have more neurons in the hippocampus part of the brain? Or maybe that neurogenesis is less or none in the hippocampus..? Also, how can you determine whether someone has a low or high working memory capacity?

The higher working memory capacity group I think can make time go by faster because they are a little more intelligent and are more willing to work harder to get the job done. More studies like the time tasks in math can help determine the lower memory groups work ethics. You can also test for the memory groups how easily distracted they are, or an IQ test would be a good test as well. How is one supposed to tell if they are part of the high or low working memory class?

For the higher memory capacity class I believe they will do better and working harder to get the job done with less distractions and to also be a little more intelligent than the lower memory pass the class. You can also test for the memory groups and what distractions affect them the most like with the timed study with the math. How is one supposed to figure out whether or not they have high or low memory capacity? Yes and IQ test would be helpful but you also need to test for the situation in which making the time go by faster.

"The intriguing finding is that time went faster for the students with higher working memory capacity. When tasked with doing the maths for four minutes, they tended to work for longer, estimating that the time was up later than the low working memory participants."I don't understand this paragraph. Surely you're saying here that the high WM participants perceived time as progressing more slowly than low WM ppts if their '4-min' maths tasks were longer than the low WM maths tasks? Help me out here.

Thank you - I think I understand this now - interestingly, I think it's more accurate to say that their estimation of time passing was slower. While they were doing the exercise time slowed down for them, as they attended to fewer internal beats; to impose a real four minute limit would have felt too soon, e.g. time had passed quicker than they thought... Anyway I suppose this is semantics.